1. Field of the Invention
This invention relates to a car door structure wherein a door trim is installed to a door inner panel, and a noise isolation sheet is installed between the door inner panel and the door trim.
2. Description of the Prior Art
As illustrated in FIG. 3, there have been a known method of isolating noise in the interior of a door 50, wherein a felt 2 or urethane is attached to the backside of an interior door trim 1 which is provided to the inner side of a door inner panel, or an urethane-made article is attached to the side of the door inner panel (See, for example, Patent Publication No. 1 and 2.).
[Patent Publication No. 1]
Japanese Examined Utility model Publication No. 5-23376
[Patent Publication No. 2]
Japanese Unexamined Patent Publication No. 10-119159
In the Patent Publication No. 1, there is disclosed a door trim which is provided with pad material made of urethane foam and the like. In the Patent Publication No. 2, there is disclosed a noise isolation cover made of urethane foam.
However, according to the above-described prior arts, the noise isolating effect is not satisfactory because the felt 2, urethane, pad material and isolation cover are all made independently and they are installed merely partially to the side of the door trim 1 or the inner side of the door inner panel.
Further, they had to be partially installed, so that there was a problem that the installation operation was troublesome.
Concerning the above-mentioned problem, the applicant of the present invention previously provided a structure wherein an isolation sheet 20 is provided between a door inner panel 11 and a door trim 12 and wherein the top end of the sheet 20 is secured to an inner weather strip 15 just like a curtain hanging from the upside to the downside (See Japanese patent application No. 2002-57777).
In this structure, the inner weather strip 15 is composed of an installation base 16, seal lip portions 17 and 18 provided up and down for elastically making contacts with a door glass 70 which slides in the upward and downward directions from inner side, and a support portion 19 which is prolonged downwardly from the installation base 16 for supporting the seal lip portions 17 and 18. There are formed a plurality of lip portions 16a and position adjustment protrusions 16b on the upper surface of the installation base 16. The installation base 16 is inserted into a concave portion 13 formed on the upper portion of the door trim 12, while each of the position adjustment protrusions 16b makes a contact with a corresponding step portion 13a for adjusting in a proper position. The door trim 12 is fixed to a door inner panel 11 with clips 30.
According to this structure, there is created two rooms X and Y between the door inner panel 11 and door trim 12 through the intermediary of the isolation sheet 20, so that the noise isolating effect improves compared to the conventional arts which are provided with a felt, urethane, pad material, noise isolation cover and the like. Further, the noise isolation sheet 20 is provided by merely hanging the sheet 20 from the upside to the downside, so that an installation operation is easy.
The door structure shown in FIG. 5 shows a sectional view along line I—I in FIG. 4. Although, this structure is such that the mounting base 16 of the inner weather strip 15 is tightly inserted into the groove 13 which is formed at the upper portion of the door trim 12, this may be structured as illustrated in FIG. 6, wherein the mounting base 36 of the inner weather strip 35 comprising the seal lip 37 is installed to the upper edge of the door inner panel 11, while the top edge of the door trim 32 is installed to the groove 33 which is formed in the inner weather strip 35.
The structure illustrated in FIG. 7 is a drawing corresponding to a sectional view along line II—II in FIG. 4, and it illustrates a car door structure the applicant of this application has previously filed (Japanese Patent Application No. 2002-233542). In this car door structure, the press portion 80 is protruded from the outer surface of the door inner panel 11 side of the door trim 52, which pushes the noise isolation sheet 20 to the surface of the door inner panel 11 at the time of an installation operation. According to this structure, since the push portion 80 is provided, a displacement or deviation of the noise isolation sheet 20 is prevented, and deterioration of the outlook of the structure is also prevented.
In recent years, sponge sheets of low density provided with the noise isolating effect as well as the waterproof effect have been deemed for use as noise isolation sheets. And, as a process of securing the edge portions (particularly the side portions and the lower end portion) of the sponge sheet, a method has been invented wherein the sponge sheet is adhered to a door inner panel with a sealer. However, since the sponge sheet is opaque, there is a problem in working properties of an installation operation that it is difficult to make sure whether or not the sponge sheet is assuredly adhered with the sealer.
In order to solve this problem, the before-mentioned structure as illustrated in FIG. 7 can be employed. However, further improvement is required to provide the method of securing the sheet more easily and assuredly performed.
Therefore, it is an object of this invention to provide a car door structure comprising a structure wherein a noise isolation sheet is easily and assuredly installed.